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When my engine fan kicks in at low temps my ac works

Customer Question

When my engine fan...

When my engine fan kicks in at low temps my ac works perfectly and the engine runs at 180 degrees all day. When the engine fan does not kick on until 200 degrees my ac does not work and the engine runs at 190 all day. I have a 2005 Volvo with an isx 450.

Mechanic's Assistant: Have you checked the Freon level?

Yes the ac system checks out perfect it has to do with the fan somehow

Mechanic's Assistant: What is the model of your '05 Volvo?

Vnl64t

Mechanic's Assistant: Are you fixing your vehicle yourself? What have you tried so far?

Yes, the mechanics have not been able to figure it out. there must be 2 sensors to turn on fan. when the one works for the ac it does not overpressure and work perfectly when it does not turn the fan on then it the ac overpressures and does not work. then the fan does not turn on until the engine reaches 200 degrees. I have replaced the high-pressure switch for the ac. did not fix the problem.

Experience: Performed various automotive repairs on several light duty and medium duty vehicles over 15 years of service.

Verified

Hi, my name is ***** ***** I will be happy to assist with this today. In some cases, I may need more info to assist better. I apologize for any delay.I try to be here most weekdays and some weekends. If you respond and I do not respond back right away I will do so as soon as I can.

It sounds like the engine coolant temp sensor is sending the correct signal to turn on at 200 but the fan is not turning on for the ac to lower the ac pressures. If you have already replaced the high-pressure switch check the wiring from the switch to see if any wiring is found to be loose or damaged in any way causing this issue here. If you have any loose or damaged wiring or wiring connections at all this will need to be corrected to resolve this fault here.

Try wiggling the wiring from the high-pressure switch with the engine running to see if it then kicks on. If it does then you know for sure there is a wiring fault.

If this was already checked let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service, your 5-star rating is appreciated ( should be a link to click on here or above). You can rate at any time and we can continue to work on your question as this will not close out your question. I work on delivering the best answer and help here but in some cases, it can be difficult to do without seeing the vehicle.

O.k., this is a medium duty vehicle. This is out of my area of expertise. I will see if I can get this switched to the medium-duty side of things here for others to see if they can help.

Unfortunately, this is all of the info I have on this myself here. Others here may be able to help further on this with the information you need. I will opt out and open your question up to everyone else here to see if they can help with this. I hope you can get this resolved with ease.

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Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.